Assessment of the rock slope stability of Fushun West Open-pit Mine

The stability of the slope is directly related to the safety operation of the open-pit and the life safety of personnel. Effective evaluation of slope stability can reduce the loss caused by slope disasters such as the Fushun West Open-pit Mine. In recent years, some damage has occurred in the south slope of the mine. Therefore, a progressive research method combining the rock mass classification system, slope mass rating method and numerical method is proposed in this study to analyze the possible failure mode and deformation mechanism of the slope. The digital photogrammetry technology, borehole television technology, infrared scanning technology, and on-site monitoring are combined to obtain the relevant data needed for the method. Based on the rock mass characteristics and the survey on-site, the quality of the rock mass of the slope was evaluated through the rock mass classification system and the borehole TV technique. The slope mass classification system with essential adjustment factors considering the discontinuities and excavation methods are a feasible method to estimate rock slope stability. Thereafter the stability of the south slope was estimated by using the slope mass rating method. The results indicate that the stability of the slope is controlled by the weak bedding plane prone to planar failure. Additionally, the deformation mechanism and potential failure dimensions were analyzed through numerical method. Incorporating the empirical result with the numerical result indicates that the south slope is in limit equilibrium state and susceptible to failure along bedding planes. The resulting of the slope stability was validated using the monitoring data that obtained by the GPS devices in situ. According to the deformation characteristics, the corresponding reinforcement methods were established and achieved good result. The progressive methodology provides an effective way to assess the stability and serves for the formulation reinforcement scheme of the rock slope in the complex geological conditions.